Maximal Midexpiratory Flow Rate

**Definition:** Measurement of rate of airflow over the middle half of a FORCED VITAL CAPACITY determination (from the 25 percent level to the 75 percent level). Common abbreviations are MMFR and FEF 25%-75%.

**Tree numbers:** - E01.370.386.700.660.225.510 - G09.772.650.300.670

**Synonyms:** - Forced Expiratory Flow 025-075 Percent - Flow Rate, Maximal Midexpiratory - MMFR - FEF 25-75 Percent